Geothermal, “old” energy for the future

Published: 2012-09-17

Enel’s research and innovation expertise is expanding the harnessing of geothermal resources. As shown by the achievements at the hybrid geothermal/solar Stillwater plant and the ongoing activities in Livorno

Improving efficiency and exploring new paths are the main two aims of innovation in the energy field. And Enel is pursuing them with constancy, obtaining achievements that place it in the frontline at a global level.

Like in the field of geothermal energy: a technology that was born in Italy over a century ago, and which is accomplishing absolutely new advances thanks to Enel’s innovation.

A demonstration of this is the Stillwater plant, developed by the Enel Group in Nevada (USA), thanks to which EGP North America won the second issue of the GEA Honors Awards for “Technological Advancement”.

Stillwater is innovative in two ways. Firstly, it uses the new binary cycle technology developed by Enel Research for the exploitation of underground mid-temperature fluids. Also, it’s the only geothermal plant in the world that is integrated into a solar photovoltaic facility.

But Enel has not only applied geothermal innovation at Stillwater. At the Experimental Area of Livorno Enel’s Research is building a cutting-edge plant that will produce electricity also from low temperature geothermal sources (130 – 170 °C) with a higher efficiency than that of other similar technologies that are being developed, near to that of high-temperature conventional plants.

The new facility (the prototype has a capacity of 500 kWe) uses a supercritical innovative organic cycle fluid (Organic Rankine Cycle, ORC), created and applied by Enel Research jointly with the Polytechnic of Milan and Turboden, an Italian company that is a leader in the field of ORC motors.

Livorno is one of the first geothermal facilities that use supercritical ORC cycles. This is another example of Enel’s leadership in guiding the development of new technologies for the efficient use of renewable sources.